A previously awarded grant allowed the TNPRC to begin the development of SPF rhesus monkey breeding colonies to provide animals for AIDS research programs. The SPF program has resulted in the successful recruitment of close to 600 animals in the first year. The objective of this application is to request funds to allow the expansion of the present TNPRC SPF rhesus breeding colonies (SPF4) and the development of a specialized SPF colony (SPF9+) which are further characterized and well suited for the needs of AIDS research. These strategies will assist in alleviating the critical national shortage of well-characterized rhesus monkeys for the AIDS research effort. The expansion of the present SPF colonies of the TNPRC will be accomplished using several strategies. Funds have been requested in this application to allow for support of a portion of the currently unsupported source colony where SPF candidate animals are derived in order to assure their ready availability. Funds for viral screening of animals and renovation of housing enclosures to better fit the need of small social group housing have been requested to expand the SPF4 colonies. An SPF9+ colony modeled after the successful "super clean" colony at the New England National Primate Research Center (NENPRC) will be developed in addition to the SPF4 colony. The TNPRC will further develop the model of the "super clean" colony by adding the testing for a number of gastrointestinal tract agents. These agents were chosen based on their relevance to AIDS research and to their clinical importance to the long term success of nonhuman primate (NHP) breeding colonies. It is anticipated that by the end of the five-year period of this grant, if awarded, 1,097 rhesus monkeys will be assigned to theSPF4 colony and 50 animals will be assigned to the SPF9+ colony. The total number of SPF4 animals in the TNPRC colony from the present colony and the proposed colony in this application is anticipated to be in excess of 2,000 animals in five years.